Can Tukysa (tucatinib) cause diarrhea, and how common is it?
Yes. Diarrhea is a known side effect of Tukysa (tucatinib). In clinical use, it can occur as part of treatment-related gastrointestinal side effects. [1]
What should I do if I get diarrhea while taking Tukysa?
Contact your oncology team promptly, especially if the diarrhea is moderate to severe, you feel dehydrated, or you cannot keep fluids down. Your prescriber may recommend anti-diarrhea treatment and, depending on severity, temporary dose interruption or dose reduction. [1]
When does diarrhea become dangerous?
Seek urgent medical care if diarrhea leads to signs of dehydration (for example, dizziness, very low urine output), is accompanied by fever, or becomes severe (for example, frequent watery stools or symptoms that don’t improve with initial treatment). Your clinician will guide whether Tukysa dosing needs adjustment. [1]
How is Tukysa-related diarrhea treated?
Management typically includes standard diarrhea measures (such as fluids to prevent dehydration) plus prescription anti-diarrhea therapy if your clinician recommends it. If symptoms are significant, dose modification may be used to reduce recurrence. [1]
Does diarrhea mean Tukysa is working?
No. Diarrhea is a possible side effect, but it is not a reliable marker of how well Tukysa is working. Treatment effectiveness is monitored with your cancer’s response using clinical and imaging assessments, not side effects alone. [1]
What else can cause diarrhea during cancer treatment?
Diarrhea can come from other causes common during cancer care, including infections, diet changes, other medicines, or treatments used alongside Tukysa (like other targeted therapies or chemotherapy). Because the cause affects management, report all diarrhea to your oncology team and ask whether testing is needed. [1]
Sources
- https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=213306